Iterate over all validation data while using limit_val_batches

DataModule
1

I have 10000s of images for training a semantic segmentation model.

I am therefore using limit_val_batches and val_check_interval.

I however note (i.e Pytorch Lightning limit_val_batches and val_check_interval behavior - Stack Overflow) that when using limit_val_batches=N, the first N batches from the underlying dataloader are returned for each validation iteration. Training therefore only every sees the first ‘N’ validation batches

Rather than using the same ‘N’ batches starting at index 0 for each validation epoch, I would like my dataloader when using limit_val_batches to sequentially chunk through all the validation data (e.g 0-19 batches the first epoch/step and then 20-39 the next)

How would I go about implementing this behavior with limit_val_batches? or is this not the expected thing to do?

2

Hey @aeolian, you can shuffle your validation dataloader so that for each epoch random images would be validated.

Also, we have recently migrated to GH Discussions for answering community questions. Feel free to ask there if you’re still having some issues.

3

Thanks @aniketmaurya. I had found GH Discussions after asking the question here and posted there also.

I have now linked the two questions.
Thank you very much for your response.